Alarm for steam-boilers



UNITED STATES PATENT OFFICE.

H. B. FERNALD, OF BOSTON, MASSACHUSETTS.

ALARM FOR STEAM-BOILERS.

Speccation of Letters Patent No. 5,870, dated November 13, 1847.

To all whom t may concern.'

Be it known that I, H. B. FERNALD, of the city of Boston, in the countyof Suffolk and State of Massachusetts, have made a new and usefulimprovement in the manner y of constructing apparatus for sounding analarm when there is a deficiency in the height of water insteam-boilers; and I do hereby declare that the following is a full andexact description thereof.

In my improved apparatus I so arrange a float within the boiler, as thatvduring the time that the height of wat-er is suflicient to prevent alldanger from its deficiency, a valve attached to said float shall closean aperture in the top of the boiler which aperture is surmounted by-asteam whistle of the ordinary construction, while in the case of theexhaustion of water so that it does not rise to the proper water line,said float shall descend, and open the valve, admitting the steam tooperate on the steam whistle, and sound an alarm.

To prevent the uncertain action of the Hoat from the foaming of thewater, I inclose said float within a cylindrical case, which hasperforations at its bottom through which water is to be admitted, forthe purpose of buoying up the float. This case has the effect ofprotecting the float from be- 'ing injuriously iniiuenced by the foamingof the water within the boiler, as said float will stand at the heightof the proper water level, or nearly so, notwithstanding its varyingheight in the boiler; this result being dependent on the admission ofthe water into the case through comparatively small openings at itslower end.

The accompanying drawing shows a vertical longitudinal section of asteam boiler, furnished with my apparatus.

A, A, is the boiler, and B, B, the float, which is surrounded by a caseC, C, somewhat larger in its interior diameter than that of the exteriorof the ioat. To keep the float concentric with the case it may befurnished with a guide pin, as at D, passing through a hole in thebottom of the case; or there may be guide strips, extending up and downwithin the case that contains the float, which will be still moreeffective. E, E, are openings at the lower end of the case through whichwater from the boiler is to pass into it.

The weight or rather the buoyancy of the float must, of course, be such,as will just cause it to keep the valve closed which is situated at itsupper end, when the water has nearly reached the lowest point to whichit may be safely allowed to descend, but which will allow said valve toopen by the descent of the float at the lowest allowable level of thewater; at all times when the water is higher than this, the said Valvewill, necessarily, be firmly closed. F, is the valve on the upper end ofthe float, and which is intended to close the aperture leading to thesteam whistle, when the water in the boiler is at the proper height, G,is the steam whistle.

Having thus fully described the nature of my improvement in the mannerof ascertaining that the water in a steam boiler is so far exhausted asto require replenishing; I do hereby declare that I do not claim theemployment of a float for the purpose of merely opening a steam valve;floats having been already used in various ways to operate on safetyvalves; but

What I do claim as constituting my invention, and desire to secure byLetters Patent, is-

The combining of a float within a steam boiler, with a case into whichwater is to be admitted through apertures in its lower part, and with asteam whistle, said float having a valve at its upper end, surmounted bya steam whistle; the whole being constructed, and operating in themanner, and for the purpose, herein fully made known.

H. B. FERNALD,

Vitnesses Trios. P. JONES, LEML. WILLIAMS,

